Existing Methods of Automated Measurement
Automated measurement of objects is currently carried out in two main ways: (i) a bulky, expensive, conventional Computer Numerically Controlled Coordinate Measuring Machine (CNC CMM) with 3 or more axes; (ii) a rigid structure of static Optical probes that is typically located in a dedicated cell at the end of the automotive production line. With a conventional CMM, the Optical probe moves in a highly controlled way around a static object to produce accurate data. In the second case, both Optical probes and object are static and localised in a calibrated way that permits accurate data. Most conventional CMMs are of either the moving bridge or horizontal arm structures; companies including Zeiss (Germany), Hexagon Brown&Sharpe (Sweden) and LK (UK) produce them. Mechanical touch probes for mounting on conventional CMMs are supplied by companies including Renishaw (UK). Optical probes for mounting on conventional CMMs are supplied by companies including Metris (Belgium). Automatic probe mounts such as the Renishaw Autojoint are repeatable to a high degree of accuracy and are supplied with a rack of probes for automatic probe changing. Rigid structures of static Optical probes are supplied by Perceptron (USA).
Existing Probe End Modules
Renishaw (UK) with the PH10M, Zeiss (Germany) and Mitutoyo (Japan) provide automated probe end modules to which contact probes such as touch trigger probes are attached. These Probe End Modules are limited to attaching just one probe and have two motorised axes. Optical probe manufacturers such as 3D Scanners (UK) and Metris (Be) have attached optical probes to probe end modules.
New Articulated Arm for Automated Measurement
A Robot CMM Arm with Exoskeleton is a new apparatus for automated measurement disclosed in PCT/GB2004/001827 by Crampton the inventor of this present invention.